1. Technical Field
This invention relates generally to agricultural harvesting combines and machines and to straw and residue chopping systems therewith, and more particularly to improvements in the concave pan portion of an integral chopper assembly, but most specifically to the provision of a replaceable grate portion of the counter knife assembly and an interruption plate downstream from the slots in the grate portion. The present invention further relates to a foreign object detection and removal system that provides a system that includes a means for retracting the counter knife assembly from the integral chopper assembly for the removal of foreign objects from the internal workings of the combine.
2. Background Art
In the operation of a typical agricultural combine that employs a threshing rotor, the flow of crop residue, sometimes referred to as material other than grain (MOG), remaining after threshing is typically discharged into a crop residue treatment and distribution system for treatment thereby and for ultimate distribution onto or over a field. Straw and residue chopper assemblies and residue spreader assemblies of various types and constructions have long been in use in or with such residue treatment and distribution systems. Such assemblies have operated to chop or pulverize the crop residue resulting from a harvesting operation into finer pieces and/or to spread the resulting crop residue, whether chopped into finer pieces by operation of a chopper assembly or passed to the spreader assembly as larger pieces of residue, onto and over the field. While such chopper and residue spreader assemblies have taken various forms, depending upon the desires of users and manufacturers, they may sometimes be identified as being of certain general types.
Many typical harvesters have traditionally employed technology and methods that have become associated with what is sometimes referred to as a hood mount chopper. Generally, such hood mount choppers can be described as flail choppers, and the systems of which they are a part have evolved to the point that they may include over 100 flail knives on a rotating chopper, mounted within a dedicated housing that provides an appropriate environment for the operation of the rotating chopper so as to best maximize its performance. The rotating chopper of such a residue management system may often operate at or above 3000 RPM and provide suitable and sufficient energy to the chopped material to be able to effect a spread of the chopped material over a width of up to 40 feet, which width generally corresponds to the cut width of the header. Such a residue management system is thus operable for its intended purpose of chopping and spreading the chopped material over a field, and generally operates effectively in such regard. With such a system, if a user does not desire to chop the straw, he may turn the chopper off and bypass, or route the material flow around, the chopper.
Typical Case IH harvesters, however, have, for over 25 years now, in an effort to provide greater equipment versatility while reducing equipment complexities, typically employed a somewhat different technology in the residue management systems thereof. Such alternative technology, the primary purpose of which has been the transport of material away from the threshing system, has utilized a multifaceted construction that affords greater versatility in the transport of such material in that such material can not only be transported, but can also be treated in varying manners dependent upon the desires of operators. Such constructions have come to be known as integral choppers or integral chopper or chopping systems due to the integration of a chopping function, in addition to the primary transport function, into the combine and its operations. Such integral chopper systems, because of their positioning within the combine and their functional capabilities, offer a versatility not generally available with the hood mounted chopper systems.
Such integral chopper systems have been so designed that, as noted hereinabove, their primary function is the transport of material away from the threshing system and a secondary function is the treatment of such material as it is being so transported. Such operations are usually effected in one of two different ways. Most commonly, the integral chopper system is operated to transport the material from the threshing system to a spreading system as a rotary chopper element or portion rotates at or near 3000 RPM so as to quickly move the material rearwardly and to also chop it into smaller pieces as it is being so transported. Less commonly, the integral chopper system is operated to more gently transport the material from the threshing system to a spreading system as the rotary chopper element operates at a much slower speed, typically at only about 800 RPM, with considerably less chopping activity. In the former instance, the desire and expectation is that the material will be transported and that the shortest mean length of cut will be realized to allow for modem minimum tillage applications while the chopping is accomplished using as little power as possible. In the latter instance, the desire and expectation is that the material will be transported in such a manner as to provide the longest and least damaged straw possible.
With reference to such integral chopper systems, the more recent integral chopper systems have typically included a residue chopper assembly that has a rotary chopper component or element disposed laterally within a housing extending generally horizontally across the flow path of the crop residue through the housing, as well as a counter knife assembly extending generally parallel to and spaced from the rotary chopper element. The counter knife assembly has included a chopper grate assembly spaced below and extending generally parallel to the rotary chopper element and a knife mounting assembly positioned generally beneath the chopper grate assembly.
The rotary chopper element of the residue chopper assembly has typically included a cylindrical tube or like member having a plurality of mounting locations distributed about its periphery, at which locations various knife blades or paddles have been mounted or affixed. Oftentimes the mounting locations and the knife blades connected or mounted thereat have been disposed in rows and columns, though sometimes in differing array configurations, about the outer surface of the rotary member so that, as the rotary member has been operated, the knife blades have served to contact and pull and push rearwardly the residue material passing near the rotary member, sometimes also cutting such residue material into smaller pieces as the residue material has been propelled rearwardly.
The chopper grate assemblies of the counter knife assemblies of such integral chopper assemblies have typically included a grate portion, often welded in place as part of the chopper grate assembly, having a plurality of holes or transverse slots spaced along its length, which holes or transverse slots have typically been so sized that smaller pieces of crop residue, which may include un-separated grain, have been able to pass therethrough and enter the combine cleaning system, at least when such holes or slots have not had other elements positioned therein or extending therethrough or have not otherwise been obstructed.
The knife mounting assemblies of such counter knife assemblies have typically included bar-like elements or components, positioned generally below the chopper grate assembly, extending in a fixed end-to-end arrangement with a plurality of spaced blade elements, often welded in place along the portion of the bar-like element generally facing the rotary chopper element, which blade elements have been aligned with slots in the grate portion of the chopper grate assembly. Such blade elements and slots in the grate portion of the chopper grate assembly have been coordinately sized and configured to permit the blade elements to be insertable into the slots to at least partially project therethrough when the knife mounting assembly is disposed in certain positions.
Often, the counter knife assemblies have had associated therewith an adjustment mechanism that has been operable to vary the spacing between the grate portion of the chopper grate assembly and the knife mounting assembly, as well as the degree of projection of the blade elements of the knife mounting assembly through the slots of the grate portion, as may have been desirable depending upon the crop being harvested. Such an adjustment mechanism has operated to move the knife mounting assembly between a fully engaged position with the blade elements of the knife mounting assembly extending through the slots towards the rotary chopper element and a fully retracted position in which the blade elements are fully withdrawn or retracted from the slots, and has typically also been operable to adjustably vary the position between a fully engaged and fully retracted position.
A counter knife assembly of such general construction, whether or not the knife mounting assembly thereof has had the capability of being adjustably repositionable relative to the grate portion by an adjustment mechanism, has often been referred to as a stationary knife assembly. Such nomenclature has been considered appropriate since such knife mounting assemblies, though perhaps adjustable to some extent to vary the distance between the rotary chopper element and the knife mounting assembly, such as by movement of the knife mounting assembly relative to the grate portion of the chopper grate assembly and the slots thereof, often in an arc-like movement about an offset axis parallel to both the rotary chopper element and the longitudinal axis of the knife assembly mounting, remain in essentially fixed or stationary positions during the chopping operation of the residue chopper assembly once they have been adjustably moved to a given position.
With such constructions, the knife blades or paddles of the rotary chopper element have cooperated with the blade elements of the knife mounting assembly when the knife mounting assembly has been positioned such that the blade elements thereof projected through the slots in the grate portion of the chopper grate assembly to both propel the residue rearwardly and to better chop the residue as it passed between the rotary chopper element and the chopper grate assembly.
Thus, in the operation of a typical combine that employs an integral chopper system, the flow of crop residue after threshing is typically discharged into a crop residue treatment and distribution system located below and rearwardly of the rear end of the threshing system, which crop residue treatment and distribution system includes the integral chopper system and its primary rotary chopper or beater apparatus or assembly that is operable to chop or beat the residue into smaller pieces as it transports and/or propels the resultant crop residue further rearwardly within a rear end of the combine for either discharge from the combine through a rear opening onto a field, or into another secondary chopper and/or spreader mounted on the rear end operable for spreading the residue over a swath of a field.
During a typical operation of such a combine, as the crop residue is discharged from the combine rotor and moves through the crop residue treatment and distribution system, it flows between the rotary chopper element of the integral chopper assembly and the chopper grate assembly thereof. When the stationary knife assembly is in an engaged position, as the crop residue is being moved and propelled rearwardly, such crop residue is also chopped into smaller pieces by the cooperative actions of the knife blades or elements of the stationary knife assembly and the knife blades or paddles on the rotating rotary chopper element. The rotational movement of the rotary chopper element, typically at or near 3000 RPM, thus serves not only to propel the resultant flow of crop residue further rearwardly, but also to effect a cutting of the material encountered by the knife blades or paddles associated therewith.
When the stationary knife assembly is positioned to a fully retracted position, however, such as might be desirable with some crops and/or for some residue, the crop residue passing between the rotary chopper element and the chopper grate assembly is moved rearwardly by the action of the rotary chopper element, but with greatly lessened chopping activity. If the rotary chopper element is rotated at a substantially lower speed, such as about 800 RPM, longer pieces of residue, with considerably less damage thereto, can be effectively transported rearwardly.
In general, it has been found that such dual and alternative transport operations of the integral chopper systems can best be realized by employing knife elements fixedly or rigidly mounted to or on the rotary member, as opposed to flail-type elements that could be mounted to lugs on the rotary member so as to be free to rotate about such lug connections, and by the use of blade elements that have a sharpened edge to efficiently and effectively cut or chop the residue, as opposed to blunt bars for beating or pulverizing such residue, as the residue passes between the rotary chopper element and the chopper grate assembly.
Such integral chopper systems, which are based upon a legacy design utilized by Case IH harvesters for approximately 25 years, have recognized advantages over hood mounted chopper systems in that they often allow combines to be manufactured with simpler designs and fewer moving parts, resulting in less expensive base units and lighter weight products, while typically performing at levels competitive to performance standards of hood mounted choppers. Despite the recognized versatility and advantages of the integral chopper systems, users have continued to seek improved systems, and have continued to present their desires and critiques of the prior art systems.
In such regard, users have continued to state their desires for an integral chopper system that can better absorb impacts with foreign objects without significant damage or breakage. In light thereof, and to address various European marketing demands, attempts have been made in more recent years to develop new types of integral chopper systems, including integral chopper systems that could utilize flail-type elements and connectors instead of fixed and rigidly mounted knife blades on the rotary element. In general, such integral chopper systems have met with limited success, due in part to difficulties in dealing with the increase in material throughput that has been experienced over the past 10 years as machine capacities, and consequent demands upon the integral position, have increased.
More particularly, at least with respect to flail-type integral chopper systems, it has proven difficult to achieve a system that can, to the desired degrees, effectively offer and provide the dual capabilities of, in one alternative, chopping into or reducing the residue to finer pieces for spreading as such residue is transported rearwardly and, in the other alternative, more gently transporting the residue, in larger pieces, rearwardly for windrowing. The use of flail-type elements and mountings in lieu of fixed and rigidly mounted knife blades on the rotary element has generally not resulted in the degree of success and satisfaction desired therefor, especially when such an integral chopper system has been operated as an 800 RPM flail chopper. In such operation, the flail-type elements, due to the lack of inertia associated therewith, have sometimes, even in the absence of heavy loading, folded back along their direction of travel and caused plugging of the harvester and consequent reliability problems. Such factor has been seen as a significant limitation to, and disadvantage of, a flail-type integral chopper as opposed to a fixed blade integral chopper.
On the other hand, such flail-type integral choppers offered one significant advantage over fixed blade integral choppers in that they could, unlike fixed blade integral choppers, better absorb energy when foreign objects, such as auger fingers or rocks, were encountered within the crop residue flow during operations. Often, with a fixed blade integral chopper, an impact with such a foreign object, especially if relatively severe, would effect mission disabling damage to a fixed blade integral chopper system, such as by cracking or breaking either or both the rotating knife blades or the stationary counter knife elements, or even snapping off the knife blade or element or breaking off its mounting, resulting in missing knife blade components and denigrating the performance of the assembly. With the flail-type integral choppers, however, the rotating flail-type elements could fold back if and when a foreign object became captured by the stationary knife elements, thereby significantly minimizing the possibility of damage to or breakage of the stationary knife elements or the rotating flail-type elements.
In addition, users have noted that, typically, the concave pan portion of the chopper grate assembly of the prior art integral chopper systems was so constructed, as by the welding of various components together, to be a major component of the integral chopper systems along and past which the residue would flow as it passed between the rotary element and the chopper grate assembly. Frequently, the wear experienced along the concave pan portion has been non-uniform, with the grate portion exhibiting the greatest wear, and with the concave pan portion therefore requiring replacement as a large component whenever the wear on the grate portion became undesirable. Such replacement of the concave pan portion, because of the size of such major component, has been cumbersome and more difficult than might otherwise have been desirable, especially when the remainder of the concave pan portion, other than the grate portion, remained generally serviceable.
Also, some users have expressed beliefs that the chop quality realizable by integral chopper systems, at least in length of cut (LOC), has remained inferior to the chop quality that could be realized by hood mounted choppers.
Consequently, attempts to develop improved integral chopper systems have continued. The ongoing challenge has been to develop an integral chopper assembly that can offer the various advantages desired while overcoming or minimizing the disadvantages that have been encountered with the prior art systems. The integral chopper system, as discussed and described hereinafter, is a newly developed system that employs various inventive concepts to realize in great part the various advantages sought therefor while overcoming and/or minimizing many of the difficulties and disadvantages associated with the prior art constructions.
Combine harvesters are also equipped with a feederhouse that lifts the cut crop into the threshing and separation areas of the combine. The grain is separated from the stalk by a rotor or threshing system. The grain is then moved and stored in a grain tank. The chaff and trash are deposited from the rear of the combine. The grain stored in the grain tank is eventually discharged through a grain tank unload tube. An operator usually runs these various operations from a glass-enclosed cab. Typically, the cab is located above and behind the header and feederhouse. There are a variety of agricultural combine harvesters and their operations are well known in the art. For examples of such harvesters reference U.S. Pat. No. 4,846,198 which illustrates the conventional and twin rotor threshing and separating systems of a harvester as well as other major systems of the harvester. See also the New Holland Super Conventional Combines TX™66, TX™68, the New Holland TWIN ROTOR® combines TR™ 89 and TR® 99 for examples of existing conventional and twin rotor harvesters. U.S. Pat. No. 4,332,262 also illustrates the primary systems of a conventional harvester. For further details regarding various agricultural harvester systems review U.S. Pat. Nos. 4,522,553, 4,800,711, 4,866,920, 4,907,402, 4,967,544 and 5,155,984. See also the New Holland corn head model 996 and the New Holland grain belt header model 994 for details regarding headers.
The previously mentioned feederhouse typically consists of a conveying chain which pushes the cut crop from the header to the front of the threshing system. The conveying chain has several crosspieces to assist in moving the crop and to ensure proper spacing. The conveying chain is powered and also positioned by a front drum and a rear drum. The front drum is positioned approximately behind the header and the rear drum is positioned approximately in front of the threshing system. As seen in FIG. 1, the drums rotate in a counter-clockwise fashion. The cut crop flow or crop mat is pushed by conveyor chain upwards along the floor of the feederhouse and towards the threshing system. Besides lifting or elevating the cut crop to the threshing and separating systems, the feederhouse provides several other functions. First, the feederhouse helps to properly position the header relative to the ground. Second, the feederhouse can be the location of a stone detection and removal means. Frequently, during farming operations, the header will inadvertently receive a stone. If the stone enters the threshing system in the combine, expensive damage will result to the threshing components. It is a critical function of a stone detection and removal system to prevent a stone from damaging the threshing system. A typical stone detection and removal system is a cylindrical stone beater or stone roll positioned near the mid-point of the feederhouse. The stone roll rotates allowing the crop mat to continue towards the rear drum and threshing system. A stone that is too large is forced from the feederhouse through a stone trap door beneath the stone roll. In addition to stones, the detection and removal system can generally function to remove any foreign object of sufficient bulk.
Unfortunately there are several deficiencies to the current feederhouse design. The stone beater design limits the thickness of the crop flow. By limiting the amount of crop flow, it takes longer to perform farming operations. Previously, acoustic instruments have been used to detect stones entering farm equipment. Typically, the stone contacts a sounding plate. The acoustic instrument monitors the sounding plate. A stone contacting the sounding plate causes the sounding plate to emit a sound above a predetermined setting. The acoustic instrument observes this sound and halts the farming operation. It has been difficult to apply this technique of stone detection to a combine harvester. Typically if a single acoustic instrument and sounding plate is used, a stone can only be detected on the side of the crop flow closest to the detector. Stones on the opposite side or center of the crop flow are undetected. There are also additional problems with the feederhouse design. A malfunction with the spring mechanism used to keep the door of conventional stone traps closed can result in crop being inadvertently forced through the stone trap door.
The prior art illustrates these and other short-comings. U.S. Pat. No. 3,675,660 discloses a combine stone trap door premised on the rock detector circuit opening the stone trap door. It is possible that that the stone may be embedded in the crop flow and not deflected to be discharged. U.S. Pat. No. 4,275,546 discloses a stone discriminator using a single sounding plate to detect stones. This approach is unable to detect stones in the upper portion of the crop flow. It has not been able to successfully detect and eject stone sufficiently to be commercially viable. U.S. Pat. No. 4,288,969 discloses an improved stone trap seal. However, because of the angle of the conveying chain, a greater amount of crop is deflected and wasted. U.S. Pat. No. 4,294,062 discloses a single sensing bar positioned at the bottom of the feederhouse and unable to sufficiently detect stones. U.S. Pat. Nos. 4,305,244, 4,322,933 and 4,343,137 illustrates a feederhouse design for a combine. The lower sensing bar is used to trigger the stone trap door. However, the single sensing bar does not sufficiently detect the stones and the angle of the conveying chain results in more crop being deflected than necessary. U.S. Pat. No. 4,355,565 uses a mechanical stone beater bar to force a stone out of the crop flow. However, if the stone is too small or flat, the stone will not be detected or ejected. Also, the stone beater is only effective at lower speeds. U.S. Pat. No. 4,353,199 illustrates a single sensing bar used in a forage harvester. U.S. Pat. No. 4,768,525 illustrates a stone ejection door mechanism for harvesting equipment having a front and rear stone trap doors. U.S. Pat. No. 4,720,962 illustrates a single sensor that can be positioned in a variety of locations on a forage harvester. U.S. Pat. No. 5,702,300 illustrates a combine rock door over center closure apparatus shows a lever used to control a stone trap door.
Accordingly, there is still a need for a foreign object detection and removal system that can effectively remove foreign objects, such as a stone, from an agricultural combine. This is especially important as stones can, for example, cause significant damage to today's improved integral chopper assemblies. The present invention satisfies this need.